Don't know if this is enough for you, but it may help at least a bit to hunt
down your problem. There is a flag -i
From man rsync
--itemize-changes, -ioutput a change-summary for all updates
this gives either a "." for no change, or a letter code for each change in "data,
time, size"
The only way I know of to determine this behavior is to use the
--link-dest option in rsync OR use the much older cp -al then rsync over
top of it method. With --link-dest a change in the file's metadata
causes rsync to duplicate the file in order to store both versions of
the metadata. With
